Internal combustion engines



Nov. 1, 1960 Filed Oct. 12, 1956 W. GLAMANN INTERNAL COMBUSTION ENGINES 5 Sheets-Sheet 1 NOV. 1, 1960 1 2,958,405

INTERNAL COMBUSTION ENGINES Filed Oct. 12, 1956 5 Sheets-Sheet 2 Nov. 1, 1960 w. GLAMANN INTERNAL COMBUSTION ENGINES 5 Sheets-$heet 3 Filed Oct. 12, 1956 Filed Oct. 12, 1956 5 Sheets-Sheet 4 NOV. 1, 1960 w, GLAMANN 2,958,405

INTERNAL COMBUSTION ENGINES Filed 001;. 12, 1956 5 Sheets-Sheet 5 Fig.8

nite States Patent INTERNAL COMBUSTION ENGINES Wilhelm Glamann, 241 'Blvd. Marcelin Berthelot, Lyons, France Filed Oct. 12, 1956, Ser. No. 615,621

Claims priority, application Germany May 24, 1950 I 12 Claims. (Cl. 192-3) .in a differential gear train so as to serve on the one side for driving a supercharger compressor for the engine and, on the other side, for driving an outgoing shaft which propels the vehicle.

The invention enables a flexible operation of such a installation to be obtained without special means of regulation and it provides means which permit the usual clutch to be dispensed with.

For an engine which drives the supercharger compressor through a difierential train, the arrangement which has always been adopted up to the present time consisted in arranging the differential train on the rear or downstreams side of the fly-wheel, and in providing the outlet of the compressed air at the rear of the compressor.

This arrangement is very troublesome and has a large number of drawbacks such that, up to the present time, they have prevented its use in mass production. In fact, the compressor is then located on the other side of the engine with respect to the fly-Wheel in a zone of the vehicle in which it is diflicult to house it, account being taken of the presence of the gear-box, the starter and other components which are necessarily located in this zone; in ad dition, the various controls of the compressor, such as the regulation of the air flow, of the speed, of the delivery pressure and the outlet piping system, must pass round the fly-wheel, which complicates the assembly and involves costly layout.

It is thus of special advantage if the compressor can be on the forward side of the fly-wheel, so that it can be mounted on the engine and can be carried by the engine so as to form a compact unit with the latter, as is usual practice when it is a matter of a direct drive by the engine.

This arrangement oifers the advantage that the manufacturer can assemble and sell the engine provided with its compressor as a single unit.

However, this is not possible without other modifications, since the fly-wheel must necessarily remain rigidly coupled to the engine shaft, which excludes the use of an epicycloidal gear train of the usual type. On the other hand, when it is desired to employ the usual means of assembly of the compressor on the engine, the usual regulating members for the quantity of air, the speed, or the delivery pressure give rise to difficulty.

To this end, the invention provides a judicious choice of the ratio of the various elements of the differential train which is such that the boost or supercharger pressure is never excessive with respect to the delivery of fuel and that it is possible to eliminate any special means of regulation, this choice being expressed by a simple rule of the form: [2208a, in which a is the speed of the compressor when it delivers only into the engine andis com- 2,958,405 Patented Nov. 1, 1960 pressing atmospheric air on the ground. to an absolute pressure of 1.6 kg. per sq. cm., the speed of the engine being six times the idling speed; b is the speed of the same compressor when delivering partly into free air through a discharge orifice, the speed of the engine being its idling speed and the speed of the outlet shaft leading to the wheels of the vehicle being equal to zero.

The invention has thus for its object an engine-compressor unit in which the compressor is driven by the engine by means of a differential train, the compressor being arranged on the engine, or at the side of the engine, on the forward side of the fly-wheel so as to form a compact assembly with the engine.

The invention has also for its object an engine-compressor unit in which the compressor ishoused on the forward side of the fiy-wheel, and in which the drive of the compressor is effected by a differential train, this differential gear being constituted in such manner that, being situated between the engine and the fly-wheel, the latter remains rigidly coupled to the shaft of the engine.

The invention has the further object of an engine-compressor unit which is not provided with a regulating device for the flow of intake air or of the speed of the compressor, in which the ratios of the different elements of the differential gear are such that the ratio of the speeds a and b of the compressor for engine speeds equal to the idling speed and to six times the idling speed under the conditions previously indicated, is such that [220.811.

The invention has also for its object certain complementary arrangements which enable the clutch and its pedal to be eliminated and to improve the efficiency and the operation while obtaining a control with a single lever.

Further objects and features of the invention will become apparent from the detailed description which follows below with reference to the accompanying. drawings, in which:

Fig. 1 shows diagrammatically an internal combustion engine with a compressor driven through a differential gear, the latter being located on the forward side of the fly-wheel;

Fig. 2 is a view of one form of construction of an engine carrying an associated compressor in accordance with the invention;

Figs. 3 and 4 are diagrams showing respectively the curves of speed and pressure of supercharging;

; Fig. 5 shows diagrammatically a device for controlling the discharge valve by means of the accelerator pedal and by automatic means;

Fig. 6 shows a detail of construction relating to a stopping device for the compressor;

Fig. 7 shows a three-way cock which enables the suction port of the engine to be put to free air and the throt tle of the delivery pipe of the compressor; and

Fig. 8 is afragmental enlarged view partly in cross section showing the gear arrangement for driving the compressor. I

Referring to Fig. 1, it can be seen that an engine 1 is associated with a compressor 2 which is driven through the medium of a differential gear 3 arranged between the engine 1 and the fly-wheel 4. In accordance with the invention, the differential and the compressor are arranged on the forward side of the fly-wheel, and the compressor is supported directly by the engine with which it forms a compact unit, as will readily be appreciated from Fig. 2.

In order to permit of the arrangement of the differential gear between the engine and thefly-wheel, the two latter continuing to be directlycoupled to each other in a rigid manner, the differential gear, combined with of direct-driven compressors.

3 a speed-increasing gear 3, is formed in the following manner:

The satellite Wheels 5 are rotatably mounted on a satellite carrier box 6 rigidly coupled on the one hand to the outlet shaft 7 of the engine and on the other hand, to a hollow shaft end or sleeve s'which rigidly supports the fly-wheel. The satellites engage with a central planetary pinion 9 mounted on the end of the shaft 10 which it drives; the shaft 10 passes freely through the sleeve 8 which it carries. The satellites engage, on the other hand, with the ring 11 through which the shaft 7 passes. freely and the latter drives the pinion 12 which is mounted on the shaft of the compressor 2. More specifically, it "will be seen that crankshaft 1' of the engine is rigidly connected with the fly-wheel 4 by means of the planetary gear support 3 and sun pinion 9 transmits the power to the ground wheels by the shaft 10. The outer gear teeth drive the compressor by the teeth 11 and the speed increasing train defined by pinions 11', 12' and 12 is directly coupled to the compressor.

The compressor 2 supplies the engine through the conduit 13, the latter passing transversely to the front of the engine and being provided with cooling fins 14. On the conduit '13 'is provided a discharge conduit 16 comprising a regulating valve which is controlled by a hand-lever 17.

With this arrangement, it is thus possible to arrange the planetary gear between the engine and the fly-wheel and in consequence the compressor can be mounted directly on the engine unit as is well known in the case However, such an arrangement would still give rise to difficulty if the usual kinds of regulator controls were provided for the compressor; now these may be eliminated if, in accordance with one of the special features of the invention, ratios are adopted for the various gears of the differential train and of the speed-multiplying train constituted by the ring 11 and the pinion 12, such that if:

a=the speed of the compressor when the latter only delivers into the engine and compresses atmospheric air at ground level to an absolute pressure of 1.6 kg. per sq. cm., the speed of the engine being six times that of the idling speed.

b=the speed of the same compressor when delivering partly to free air through a discharge orifice, the speed of the engine being idling speed, and the speed of the outlet shaft leading to the wheels of the vehicle being equal to zero;

b is equal to or greater than 0.8a.

In the conditions of such a choice, the boost or supercharging pressure will not be excessive with respect to the delivery of fuel, and all special means of regulation can be dispensed with.

If it is assumed that the speed of the compressor is: a=4,000 r.p.m., for an engine speed equal to six times 400 r.p.m. (the idling speed) and thus equal to 2,400 r.p.m.

In accordance with the rule of the invention for the idling speed of the engine, namely 400 rpm, and the outlet shaft to the wheels being locked, the speed of the compressor will be at least 3,200 r.p.m.

This clearly shows the difference as compared with a direct drive or a drive based on a different choice for the members of the differential train. In these two cases, the speed of the compressor for the speed of idling of the engine would be of the order of 700 r.p.m. and not a minimum of 3,200 r.p.m.

Figs. 3 and 4 which show the curves of speed and pressure of the compressor serve to illustrate the foregoing indications. In the curves of Fig. 3, the speed V of the compressor is plotted as a function of the speed V of the outlet shaft. At each point there passes an oblique straight line along which the speed of the engine V is constant and equal to V m being thus the parame'terof these lines.

For reasons deduced from the determining equation of the differential train, the different speeds of the engine V, are necessarily proportional to the distances of these straight lines (V =a constant) from the zero point.

With a direct drive of the compressor, without the intermediary of a differential train, the location of all the speeds of the compressor is determined by a straight line I which passes through the origin 0. On the other hand, there have been drawn in Fig. 3 curves L and M which represent the speeds of compressors; respectively rectilinear and centrifugal, under the conditions of drive in accordance with the present invention.

In Fig. 4, there have been drawn the curves 1, L and M of the supercharging'pressures corresponding to the curves l, L and M.

Amongst the family of parallel straight lines V there has been drawn in Fig, 3 the straight line V which corresponds to the idling speed of the engine and the straight line V, which corresponds to a speed which is six times greater.

The curve L corresponds to the operation of the power installation with a straight-line or rectilinear compressor. By slowing down the vehicle on full load, for example on a steep slope, the curve of speed of the compressor L becomes closer, for a certain low speed of the vehicle, to the line V,, which means that the engine speed has fallen to its idling speed. Its speed cannot fall any further without risk of stalling the engine, and that is why the discharge device 15 is arranged so as to open when the vehicle continues to slow-down on a hill. At this moment, the speed of the compressor increases (the part branching upwards towards the top of the curve L), the speed of the engine still remaining at the idling speed V When the vehicle stops, the curve L re-joins the vertical ordinate at a point B. The distance of this point with respect to the horizontal ordinate indicates the speed v=b of the compressor, since the speed V' of the outlet shaft A is at this moment equal to zero, and since the speed V of the engine is the idling speed V On the right hand side of the diagram, the point A represents the point of intersection of the line L and the oblique straight line V along which the speed of the engine is six times the idling speed. For the point A, the pressure of supply should be 1.6 kg. per sq. cm., as has been shown in Fig. 4.

The distance of the point A with respect to the horizontal ordinate gives the speed at since the speed of the engine is six times the idling speed and since the pressure of supply is 1.6- kg. per sq. cm., the discharge device 15 being closed.

The rule formulated in accordance with the invention dictates that the ordinate b of the point V shall be at least equal to 0 .8 times the ordinate a. of the point A.

It is to be noted that in practice an infinite number of curves L is possible, and that the pressure of supercharging at the speed V, of the engine does not at all require to be 1.6 kg. per sq. cm. The curve L has been drawn in order to explain the conditions as clearly as possible which it is essential to observe in accordance with the present invention.

Any particular point Z of the field of speeds in Fig. 3 may be obtained during the running of the vehicle, on the condition that on the one hand the supercharging pressure is not too high and, on the other hand, that the speed of the compressor does not become too low to be of practical interest.

The curve M corresponds to operation with a centrifugal compressor. The characteristics of these compressors impose a shape other than that of the curve L, although the supercharging pressure follows roughly the same form (see L, M, Fig. 4). On the other hand, it is not possible in the case of use of a centrifugal compressor, to reduce the driving torque of the compressor by the opening of a discharge device when the speed of the vehicle falls (on ahill' and "under power) and when the aessnoa idling speed of the engine is reached. Thus, in order to prevent the engine being stalled, it becomes necessary in this case to disengage the engine by means of a clutch.

From this moment, the engine obviously does not supply any more power and the curve of speed of the compressor again falls towards zero. This is shown by the deflection towards the bottom of the curve M at low vehicle speeds. In order to obtain the point V' corresponding to the points B in the case of the straight-line compressor, the curve M can be extended in its normal trajectory up to intersection with the straight-line of the vertical ordinates. Another way of obtaining the ordinate of the B consists in calculating this speed from the numbers of teeth of the pinions interposed in the transmission between the engine shaft and the compressor shaft.

It will be observed in Fig. 3 that in the example of the curve M, the value b (corresponding to the vertical displacement of the point B) is greater than the value a (corresponding to the vertical displacement of the point A). In this way, the condition that b shall be at least equal to 0.8a is observed.

The utilisation of a clutch to disconnect the engine from the differential gear and also from the compressor is of course also possible with a compressor of the rectilinear type.

Whilst retaining the usual clutch and even the ordinary gear-box, the power unit in accordance with the invention has always:

(1) The advantage of the steeply-rising curve of torque at low speeds.

(2) The advantage that during economical running, the power applied to drive the compressor is reduced in the same measure as the torque, and

(3) The advantage that the smoke limit is further removed, since the compressor tends to supply as much air as fuel is supplied to the engine.

In this way, when so desired, it is possible with an engine of small size to obtain running conditions which are substantially superior to those which are usually obtained with a powerful engine.

It is possible, in the installation in accordance with the invention, to obtain by virtue of the valve 15, a control of the installation by means of a single pedal, while eliminating the ordinary clutch. To this. end, the lever 17 of the valve 15 is coupled to the accelerator pedal. Fig. 5 shows an example of an embodiment of this kind, the discharge device being in this case presented in the form of a valve 28 which is shown open in its position of rest.

The accelerator pedal 37 actuates the discharge device through the intermediary of a rod system 35, 36 and a lever 29 in such manner that the discharge device 28 is progressively closed when pressure is applied to the accelerator pedal. The discharge device remains partly open however as long as the vehicle has not attained a predetermined speed.

The complete closure of the valve 28 is obtained by way of example, as shown in Fig. 5, by means of a piston 38 subjected to the pressure of the liquid which is compressed by a gear-pump 39 driven by the shaft 40 which leads to the wheels of the vehicle. The pressure of the liquid increases in proportion as the speed of the vehicle increases and acts on the piston 38 to close the discharge device 28 finally, above a certain speed of the vehicle. The discharge device is thus influenced, in addition to its control by the accelerator pedal, by an independent means.

In a further form of embodiment, the separate means may be constituted by the pressure of air in the pipe 27, which prevents the complete closure of the discharge device, above a certain value of pressure, by the opposing action of the said pressure.

The single-pedal control is effected as follows:

(1 Starting The discharge device is open, the accelerator pedal being in its initial position. The compressor starts to rotate at the same time as the engine and delivers almost without pressure. These conditions correspond to the point B of Fig. 3.

(2) Setting in motion By depressing the accelerator pedal, the discharge device is displaced towards its closed position. The compressor begins to be partly loaded, and its pressure and the engine torque increase. The speed of the compressor falls while the engine speed does not vary Substantially from its idling speed (note the shape of the beginning of the curve L in Fig. 3). The vehicle starts to move away.

(3) Running At a certain minimum speed, the discharge device 15 or 28 is entirely closed. At this moment, the lowest point of the curve L has been reached. If, from then onwards, pressure is continued to be applied to the accelerator pedal, the speed of the compressor again begins to increase, simultaneously with the speed of the engine and of the vehicle. The supercharging pressure is continuously and automatically adapted to the resistance to the forward movement of the vehicle, and follows for example, the curve L shown in Fig. 4.

In this analysis of the control of the vehicle, the use has been assumed of some kind of speed regulator of the injection pump. In consequence, the speed of the engine is determined by the position of the accelerator pedal, and at the beginning of its travel, the speed remains close to the idling speed, whilst enabling the engine to supply its full power.

During prolonged running at reduced power, the power absorbed by the compressor is in principle much less than with a direct drive, without the intermediary of a difierential train, if the maximum supercharging pressure is assumed to be the same. In order further to avoid the loss of this part of the power of the compressor, it is proposed to brake and to stop the compressor at low values of engine power, this action being effected at will or automatically as a function of the position of the toothed rack or of the supercharging pressure.

This may be effected, as shown by way of example, in Fig. 6. On the transmission shaft 45 which drives the compressor, a dog 48 is mounted on splines so as to slide in the longitudinal direction and to engage with a dog 49. By acting on a lever 47, the dog 48 may be engaged so as to stop the compressor.

This operation may be carried out in accordance with the position of the rack of the ejection pump by means of a valve 43 which controls the pressure on both sides of a piston 42 which acts through the medium of a spring 41 on the lever 47.

When the compressor is stopped, it is proposed to open an orifice in the delivery pipe of the compressor to free air, in order that the engine may take-in air through that orifice. An orifice of this kind is shown in Fig. 1

device consists of a valve 51 which enables the delivery side 54 of the compressor to be closed, and at the same time opens an orifice 56 to free air.

The arrows drawn in full lines in Fig. 7 indicate the direction of flow for normal running. During braking, these arrows reverse in direction, as shown in dotted lines. It is then proposed to eventually brake the compressor by closure of the normal suction side 55, for example by means of a valve 57, and to couple the action of this closure to the action of the brake pedal in such manner that the valve 57 closes automatically at the moment of braking.

It should however be observed that the above arrangements are not absolutely essential to the operation of the power installation forming the subject of the invention. When, in accordance with usual practice, a high depression exists in the admission pipe of the engine when braking, there is no need to stop the compressor. Also, a stopping action of this kind is useless for economic running if the small less is taken into account, which is caused by the drive of the compressor working on a low back-pressure and if the slight increase in the maximum speed of the vehicle is foregone, which may be. obtained by stopping the compressor during economical running.

In the case of the use of the centrifugal compressor, the discharge device, in addition to its use as a means of discharging excess air at low engine speeds, is used to avoid a possible pumping action. By way of example, in order to obtain this effect, the regulation may be effected as a function of the speed of the air taken from a suitable point of measurement, for example 60 in Fig. 1.

I claim:

1. A power unit for an automobile having ground Wheels, comprising an internal combustion engine provided with a crankshaft, a flywheel, a differential gear assembly between the engine and the flywheel, said differential gear assembly including a carrier, planet gears on the carrier and a sun gear, the carrier rigidly connccting the flywheel to the crankshaft, an output shaft for driving the ground wheels with said sun gear operatively connected to the output shaft to transmit movement thereto, a compressor serving to supercharge the engine, and gear means driven by said planet gears for operating the compressor.

2. A power unit as claimed in claim 1 in which said gear means is a speed-multiplying gear mounted between the engine and the flywheel.

3. A power unit as claimed in claim 1 in which said carrier is permanently and rigidly fixed to the flywheel.

4.- A power unit for an automobile having ground wheels, comprising an internal combustion engine provided with a crankshaft, a flywheel, an accelerator pedal, a differential gear assembly between the engine and the flywheel, said differential gear assembly including a carrier, planet gears on the carrier and a sun gear, the carrier rigidly connecting the flywheel to the crankshaft, an output shaft for driving the ground wheels with said sun gear operatively connected to the output shaft to transmit movement thereto, a compressor serving to supercharge the engine, gear means driven by said planet gears for operating the compressor, a discharge conduit coupled to'the delivery side of the compressor, a contirollable discharge device coupled to said discharge conduit, a control member for said discharge device and means for operably associating said control member with said accelerator pedal so that the discharge conduit is progressively closed as the accelerator pedal is progressively depressed.

5. -A power unit as claimed in claim 4, including means preventing said discharge device from fully closing the said discharge conduit untilthe automobile has reached a predetermined speed.

6. A power unit as claimed in claim 1, further including separate means for controlling said discharge device in addition to the accelerator pedal.

7. A power unit as claimed in claim 6, wherein the said separate means is constituted by a control piston operated by a pressure which is a function of the speed of the output shaft of the said differential gear assembly which propels the said automobile.

8. A power unit for an automobile having ground wheels, comprising an internal combustion-engine provided with a crankshaft, a flywheel, a differential gear assembly between the engine and the flywheel, said differential gear assembly including a carrier, planet gears on the carrier and a sun gear, the carrier rigidly connecting the flywheel to the crankshaft, an output shaft for driving the ground wheels with said sun gear operatively connected to the output shaft to transmit movement thereto, a compressor serving to supercharge the engine, gear means driven by said planet gears for operating the compressor,

means for stopping the rotation of said compressor and accelerator means operably associated with said stopping means to stop the compressor when the accelerator means is depressed.

9. A power unit as claimed in claim 8, further including a delivery pipe for said compressor, said delivery pipe being provided with a secondary orifice, a control valve associated with the secondary orifice, and means being cooperable with said control valve to open said valve during operation of the compressor and to close the valve when the compressor is stopped.

10. A power unit as claimed in claim 8, further including a delivery pipe for the compressor, the engine having a suction port, a three-way valve being provided in said delivery pipe, and means being provided to move said valve to a position to close said delivery pipe and to place said suction port into communication with free air.

11. A power unit as claimed in claim 1, in which the dimensions of the gears of the said difl erential are chosen in such manner that where:

a=the speed of the compressor when the said compressor only delivers into the engine and compresses atmospheric air at ground level to an absolute pressure of 1.6 kg. per sq. cm., the speed of the engine being six times the normal idling speed, and

b=the speed of the same compressor when delivering partly to free air, the speed of the engine being its normal idling speed and the speed of the outgoing shaft leading to the wheels of the vehicle being equal to zero:

b is at least equal to 0.8a.

12. A power unit as claimed in claim 1 in which the dimensions of the gears of said differential and a speed multiplying gear interposed between said differential and said compressor, are chosen in such a manner that where:

a=the speed of the compressor when the said compressor only delivers into the engine and compresses atmospheric air at ground level to an absolute pressure of 1.6 kg. per sq. cm., the speed of the engine being six times the normal idling speed, and

b=the speed of the same compressor when delivering partly to free air, the speed of the engine being its normal idling speed and the speed of the outgoing shaft leading to the wheels of the vehicle being equal to zero:

b is at least equal to 0.8a.

References Cited in the file of this patent UNITED STATES PATENTS 1,732,405 Invernizzi Oct. 212, 1929 2,404,323 Staley July 16, 1946 2,528,745 Fisher Nov. 7, 1950 2,579,643 Baak Dec. 25, 1951 FOREIGN PATENTS 929,461 France Dec. 29, 1947 619,978 Great Britain Mar. 17, 1949 

